The present invention relates to a drainage device including a disposable collection chamber and a nondisposable suction control chamber so that only the collection chamber need be discarded after use of the drainage device.
Chest drainage devices in which all of the operating parts are disposed within a single integral unit are well known in the art. U.S. Pat. No. 3,363,626 is an example of an early design of such a device. It is also known to construct thoracic drainage devices in separate modules so that a drainage device of a single or multiple bottles may be constructed. U.S. Pat. No. 3,847,152 is an example of such a device.
More recently, thoracic drainage devices have been provided with more complex internal elements to provide the physician with more information with regard to the patient's condition. Such drainage devices in many cases eliminate the need for partially filling certain of the chambers of the device with water prior to use. Typical of such dry drainage devices is that disclosed in U.S. Pat. No. 4,605,400 which discloses a device having valves to regulate the suction as well as to provide a one way valve means to prevent atmospheric air from entering the collection chamber. In addition, the device disclosed in U.S. Pat. No. 4,605,400 provides a bellows for indicating the respiration of the patient. Obviously, the additional structural elements provided in the drainage device shown in U.S. Pat. No. 4,605,400 substantially increases the cost of the drainage device and it has been necessary to consider modifying the device so as to decrease the cost to the patient substantially while still retaining the advantages of providing the physician with the diagnostic tools shown and described in U.S. Pat. No. 4,605,400.
There have been provided in the prior art a number of drainage device having collection chambers which may be disconnected from the remainder of the device. U.S. Pat. Nos. 4,439,190; 4,569,674 and 4,105,031 are typical of such devices. Such devices do not, however, provide a means for maintaining sterility of the operating elements of the drainage device in a separate nondisposable section with releasable locking means being provided between that section and a collection chamber which is provided with means for preventing liquids from flowing from the collection chamber into the nondisposable section of the apparatus.